<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
    <div v-show="!isLogin">
        <a href="javascript:void (0)">注册</a>
        <a href="javascript:void (0)" @click="login()">登录</a>
    </div>
    <div v-show="isLogin">
        <input type="text" v-model="newName">
        <a href="javascript:void (0)" @click="add()">添加</a>
        <a href="javascript:void (0)" @click="logout()">登出</a>
    </div>
    <ul>
        <li v-for="name in names" v-text="name"></li>
    </ul>
</div>
<script src="https://lf3-cdn-tos.bytecdntp.com/cdn/expire-1-M/vue/2.6.14/vue.js"></script>
<script>
    let v = new Vue({
        el: "div",
        data: {
            names: ["刘备", "关羽"],
            isLogin: false,
            newName: ""
        },
        methods: {
            login: function () {
                v.isLogin = true;
            },
            logout: function () {
                v.isLogin = false;
            },
            add: function () {
                v.names.push(v.newName)
            }
        }
    })


</script>
</body>
</html>